[R] transform R function

[lamack lamack]

Dear all, Why the transform function does not accept two statistics 
functions?

a = data.frame(matrix(rnorm(20),ncol=2))

transform(a,M.1=mean(X1),M.2=mean(X2)) # does not works

#while:

transform(a,M.1=mean(X1),M2=log(abs(X2))) #works

Best regards

JL

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